Holland’s RIASEC (Realistic, Investigative, Artistic, Social, Enterprising, and Conventional) career theory is generally recognized as one of the most important and influential in the field of career development and vocational psychology. We examined data that might verify such an observation, and we used bibliographic research tools to identify all of the publications from 1953 to 2011 on this theory. We categorized the number of citations into five areas: (a) application of the theory in practice, (b) research and practice directed to specific populations (e.g., K–12, age, occupation), (c) tools or instruments operationalizing the theory, (d) validity and efficacy of RIASEC theory, and (e) diverse populations studied in terms of ethnicity, disability, and status. We located a total of 1,970 reference citations to Holland’s theory and applications during the 58-year period, and this article describes the methods, findings, and implications of this research.